Technical Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to the assignment of resources for use in uplink transmissions in a wireless communication system.
Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
In many modern wireless communication systems, to enable a high level of control over power usage, mobile stations can take any of various different states based on their needs at any particular time. For example, a spectrum of these states can include a state with dedicated resources assigned to the mobile station; various levels of standby states having corresponding tiers of communication capabilities, and idle modes with little to no wireless connectivity. Within the various standby states, the network may have a reduced level of control over the various mobile stations throughout the cell.
In a particular example, in a conventional 3GPP UMTS network, one of the standby states is referred to as Cell_FACH. According to current specifications, the network is limited in that uplink transmissions from all the mobile stations in Cell_FACH throughout a cell must utilize the same kind of resources as one another. That is, all mobile stations in Cell_FACH within the cell are required to utilize the same transmission time interval for uplink transmissions on the E-DCH channel. This can result in a disadvantage, since some of the mobile stations in Cell_FACH may benefit from one transmission time interval, while other mobile stations in Cell_FACH may benefit from a different transmission time interval. Thus, there is a desire for increased flexibility in the assignment of resources to mobile stations for use in uplink transmissions.
As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.